Segment-ester polycarbonates can be formed into articles of various shapes including thin films. It is also desirable to provide segment-ester polycarbonates having improved resistance to high heat distortion thereby enabling these segment-ester polycarbonates to be used in forming objects that will be exposed to an elevated temperature environment, such as components exposed to automobile and aircraft applications, automobile headlamps, and the like.
Polycarbonate compositions having resistance to high heat distortion are disclosed in U.S. Pat. No. 4,180,651. This property is imparted to the high molecular weight aromatic polycarbonate resins by controlling the degree to which particular diphenols are halogenated so that there are obtained either highly pure dihalogenated diphenols or predetermined statistical mixtures comprising predominently mono and di- halogenated diphenols together with some unreacted diphenol. However, there is no suggestion of high molecular weight, segment-ester polycarbonates or the resistance of said segment-ester polycarbonates to high heat distortion when they contain moieties, fractions or portions of the bisphenol of cyclohexanone shown herein.
Among the copolyester-carbonates and the methods for preparing them which are known in the prior art, are those disclosed in U.S. Pat. No. 4,189,549 which discloses polyestercarbonate compositions which are obtained from a melt polymerization process employing para-hydroxy benzoic acid.
In general, the prior art references recognize that resistance to high heat distortion can be imparted to polymer compositions by manipulating and altering the building blocks from which the polymers are obtained and further recognizes that certain polycarbonate compositions have resistance to high heat distortion when halogenated bisphenols (diphenols) are used in the building block. However, these references do not disclose or suggest that a high molecular weight segment-ester polycarbonate composition having resistance to high heat distortion can be obtained by incorporating specific bisphenol moieties, fractions or portions as the bisphenol-carbonate moiety, or portion in a segment-ester polycarbonate composition.